▎ 摘　　要

In this article, novel designs of two different types of graphene-based absorbers of arbitrary geometry have been investigated. The first absorber uses a graphene sheet and an array of metallic patches on silicon substrate for dual-band absorption without the application of chemical potential. The second absorber is formed of a combination of graphene and metallic patches on the same substrate and is tunable over the frequency range 6.2-6.6 THz. Tunability is employed by electrostatic biasing of graphene patches from 0.4 to 1 eV. Using only a single layer of patterned graphene patches of two different sizes loaded around a square-shaped metallic patch on SiO2 substrate, an absorption bandwidth of 500 GHz is exhibited. The proposed absorbers are analyzed rigorously by an equivalent circuit model (ECM). The validation of ECM analysis is done through full-wave simulations in CST 2021.